Air filter



FIG. 1 is a front perspective view from above of a first embodiment of the claimed design;

FIG. 2 is a top view of the claimed design of FIG. 1;

FIG. 3 is a bottom view of the claimed design of FIG. 1;

FIG. 4 is a front view of the claimed design of FIG. 1;

FIG. 5 is a rear view of the claimed design of FIG. 1;

FIG. 6 is a right side view of the claimed design of FIG. 1; and,

FIG. 7 is a left side view of the claimed design of FIG. 1.

The ornamental design that is claimed is shown in solid lines in the drawings. The broken lines in the drawings are for illustrative purposes only and form no part of the claimed design. The dot-dash lines in the drawings represent the boundaries between the claimed and unclaimed areas. 

CLAIM I claim the ornamental design for an air filter, as shown and described. 